Railway switch with lubricious liner

ABSTRACT

A railway switch system includes a base plate that has an exterior surface and a movable elongate rail that has a mounting flange that has an exterior surface that faces the exterior surface of the base plate. The railway switch system includes a lubricious liner disposed between the base plate and the mounting flange and mounted in parallel engagement on top of a substrate that is one of: the exterior surface of the base plate, the exterior surface of the mounting flange, and an exterior surface of an intervening plate disposed between the base plate and the mounting flange. The lubricious liner has an exposed bearing surface, has a second width, extends continuously across the second width, and is substantially planar. The lubricious liner consists of a non-metallic graphite free material consisting of a blend of polymer resin, fibers and a lubricant.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to commonly owned and co-pending U.S. Provisional Patent Application Ser. No. 63/110,451 filed Nov. 6, 2020, the entirety of which is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to a maintenance-free railway switch having a lubricious liner therein and wherein the lubricious liner is a non-metallic substantially graphite free material consisting of a blend of polymer resin, polymer fibers and a polymer lubricant.

BACKGROUND

A railroad switch is used to allow a train to transition from one rail line to another. In order to perform this function, a set of switching rails must be moved horizontally to determine which rail line the train will be directed to. As shown in FIG. 8, the prior art technology to allow the movement of the switching rails generally consists of a steel switch plate 7 mounted/welded to a sub-plate 1 which is mounted to a railroad tie 6. The stationary rail 2 is mounted to the sub-plate 1 and retained against an edge of a switch plate 7 which serves as a stop block. A switching rail 3 is set on top of the switch plate 7 and, when actuated, slides laterally across the switch plate surface, towards or away from the stationary rail 2, to determine a rail car's direction of travel. The interface between the switch plate 7 and the switching rail 3 is typically greased 8 with a “low viscosity lubricant” to penetrate the faying surfaces and provide a boundary layer of lubricant that can shear, reducing the system friction. The problem with low viscosity lubricants is they easily move in and out of the load zone, especially when contaminated or flushed with water or other fluids, ice or snow. Displacement of the lubricants also can create environmental contamination of the soil proximate to the rails. Due to displacement of the lubricants, continued maintenance and application of lubricants is required which requires dedicated maintenance services and potentially exposing personnel to extreme conditions (e.g., long travel time required for personnel to reach remote switches and creating safety hazards by endangering personnel on active rails) while servicing the switch plates. In addition, the introduction of external contaminates such as sand and dust, in conjunction with various temperature extremes, can cause the lubricated surface friction to increase dramatically, causing the switch to fail.

Thus, there is a need for an improved railroad switch that addresses the foregoing problems.

SUMMARY

The present invention includes a railway switch system that includes an elongate rail (e.g., a switching rail) that has a mounting flange thereon. The mounting flange has a first exterior surface. The railway switch system includes a base plate that has a second exterior surface that faces the first exterior surface. The elongate rail is supported by and is laterally movable relative to the base plate. A lubricious liner is disposed between the base plate and the mounting flange and is mounted in parallel engagement on top of a substrate. The substrate is one of: (a) the first exterior surface of the mounting flange, (b) the second exterior surface of the base plate, and (c) a third exterior surface of an intervening plate disposed between the base plate and the mounting flange. The lubricious liner: (i) has an exposed bearing surface, (ii) has a first width, (iii) extends continuously across the first width, and (iv) is substantially planar. The lubricious liner consists of a non-metallic substantially graphite free material consisting of a blend of polymer resin, polymer fibers and a polymer lubricant.

In some embodiments, the polymer resin is selected from the group consisting of nylon, polyester, epoxy, silicate, nitrile phenolic, phenolic or polyimide resins.

In some embodiments, the polymer fibers are thermoplastic fibers comprising at least one of an aramid, glass, polytetrafluoroethylene and polyether ether ketone.

In some embodiments, the polymer lubricant includes polytetrafluoroethylene and/or polyether ether ketone.

In some embodiments, the lubricious liner is bonded to the substrate.

In some embodiments, the lubricious liner is mechanically secured to the substrate by at least one of an epoxy, an adhesive and mechanical fasteners.

In some embodiments, the base plate is secured to a sub-plate by at least one of welding and mechanical fasteners.

In some embodiments, the exposed bearing surface is in sliding engagement with one of the first exterior surface, the second exterior surface and the third exterior surface.

In some embodiments, the railway switch system includes one or more scrapers (e.g., a brush and a flexible material) secured to the mounting flange and in sliding engagement with the exposed bearing surface of the lubricious liner.

In some embodiments, the railway switch system includes a counter-face layer removably retained on the elongate rail and in sliding engagement with the exposed bearing surface of the lubricious liner.

In some embodiments, the railway switch system includes a scraper (e.g., a brush or a flexible material) secured to the counter-face layer and in sliding engagement with the exposed bearing surface of the lubricious liner.

In some embodiments, the railway switch system includes a counter-face layer removably retained on the first exterior surface of the base plate and in sliding engagement with the exposed bearing surface of the lubricious liner.

In some embodiments, the elongate rail extends along a longitudinal axis thereof and the mounting flange has a second width measured perpendicular to the longitudinal axis. The first width of the lubricious liner is at least as great as the second width of the mounting flange.

In some embodiments, the lubricious liner includes one or more grooves extending at least partially into the exposed bearing surface of the lubricious liner. The grooves are configured to receive and discharge wear debris and contamination.

There is disclosed herein a railway switch system that includes an elongate rail that has mounting flange thereon. The mounting flange has a first exterior surface. The railway switch system includes a base plate that has a second exterior surface that faces the first exterior surface. The elongate rail is supported by and laterally movable relative to the base plate. A lubricious liner is disposed between the base plate and the mounting flange and mounted in parallel engagement on top of a substrate, the substrate being the second exterior surface. The lubricious liner: (i) has an exposed bearing surface, (ii) has a first width, (iii) extends continuously across the first width, and (iv) is substantially planar. The lubricious liner consists of a non-metallic substantially graphite free material consisting of a blend of polymer resin, polymer fibers and a polymer lubricant. The railway switch system includes a counter-face layer removably retained on the mounting flange and in sliding engagement with an exposed bearing surface of the lubricious liner.

There is further disclosed herein a railway switch system that includes an elongate rail that has a mounting flange thereon. The mounting flange has a first exterior surface. A counter-face layer is removably retained on the mounting flange. The railway switch system includes a base plate that has a second exterior surface that faces the first exterior surface. The elongate rail is supported by and is laterally movable relative to the base plate. A lubricious liner is disposed between the base plate and the mounting flange and is mounted in parallel engagement on top of a substrate, the substrate being the counter-face layer. The lubricious liner: (i) has an exposed bearing surface, (ii) has a first width, (iii) extends continuously across the first width, and (iv) is substantially planar. The lubricious liner consists of a non-metallic substantially graphite free material consisting of a blend of polymer resin, polymer fibers and a polymer lubricant. An exposed bearing surface of the lubricious liner is in sliding engagement with the second exterior surface of the base plate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the railway switch system of the present invention;

FIG. 2 is a perspective view of another embodiment of the railway switch system of the present invention;

FIG. 3 is a perspective view of another embodiment of the railway switch system of the present invention;

FIG. 4 is a cross sectional view of a portion of the railway switch system of FIG. 1 and including a scraper system;

FIG. 5 is a cross sectional view of a portion of the railway switch system of FIG. 2 and including a scraper system;

FIG. 6 is a cross sectional view of a portion of the railway switch system of FIG. 3 and including a scraper system;

FIG. 7 is a perspective view of the lubricious liner of FIGS. 1-6 shown with grooves from in a surface thereof; and

FIG. 8 is a perspective view of a prior art railroad switch.

DETAILED DESCRIPTION

As shown in FIG. 1, a railway switch system of the present invention is generally designated by the numeral 10. The railway switch system 10 includes a stationary rail 2 in proximity to a movable switching rail 3, shown in dashed lines in FIG. 1. While FIG. 1 shows only short segments of the stationary rail 2 and the switching rail 3, each of the stationary rail 2 and the switching rail 3 are elongate members that form a switching section of a rail track. For example, the switching rail 3 is an elongate member that extends along a longitudinal axis L thereof. The switching rail 3 has a railcar wheel bearing surface 3B that is connected to a mounting flange 3F by a neck segment 3N. The stationary rail 2 is configured similar to the switching rail 3 and has a railcar wheel bearing surface 2B that is connected to a mounting flange 2F by a neck segment 2N.

As shown in FIG. 1, the mounting flange 24 of the stationary rail 2 is fixedly mounted to a sub-plate 1, for example by a metallic weld or using mechanical fasteners such as threaded fasteners, nails or spikes. The sub-plate 1 is fixedly mounted to a railroad tie 6. The railway switching system 10 includes a base plate 5 (e.g., a switching plate) that is fixedly secured to the sub-plate 1, for example by a metallic weld or using mechanical fasteners such as threaded fasteners, nails or spikes. An edge 2E of the stationary rail 2 abuts a mating edge 5E of the base plate. The switching rail 3 is supported by and is laterally movable relative to the base plate 5.

As shown in FIG. 1 the mounting flange has a first exterior surface 3X that faces away from the railcar wheel bearing surface 3B (e.g., shown facing downwardly in FIG. 1 toward the sub-plate 1). The base plate 5 has a second exterior surface 5X that faces the first exterior surface 3X. A lubricious liner 4 is disposed between the base plate 5 and the mounting flange 3F and is mounted in parallel engagement on top of a substrate, for example, in one embodiment the substrate is the second exterior surface 5X of the base plate 5. In some embodiments, the lubricious liner 4 is bonded to the substrate, for example, bonded to the second exterior surface 5X of the base plate 5. In some embodiments, the lubricious liner 4 is mechanically secured to the substrate (e.g., to the second exterior surface 5X of the base plate 5) by at least one of an epoxy, an adhesive and mechanical fasteners.

As shown in FIG. 1, the lubricious liner 4 has an exposed bearing surface 4X thereon and that faces away from the base plate 5. The lubricious liner 4 has a first width W1 that extends perpendicular to the longitudinal axis L. The lubricious liner 4 extends continuously across the first width W1 and substantially (e.g., 80 percent or more) covers the base plate 5. The lubricious liner 4 is a substantially planar thin (e.g., 0.5 mm to 3.0 mm thick) layer of material. In some embodiments, the first width W1 is greater (e.g., 1.5 times greater, 2.0 times greater) than a second width W2 of the second exterior surface 3X of the mounting flange 3, the second width W2 being measured perpendicular to the longitudinal axis L.

The lubricious liner consists of a non-metallic substantially graphite free (i.e., an amount of graphite that is low enough that the graphite contribute little or no lubrication) material consisting of a blend of polymer resin 4R, polymer fibers 4F and a polymer lubricant 4L. The polymer resin 4R is one of, epoxy, silicate, nitrile phenolic, phenolic or polyimide resins. The polymer fibers 4F are thermoplastic fibers for example one or more of an aramid (for example nylon), polyester, glass, polytetrafluoroethylene, and polyether ether ketone. The polymer lubricant 4L a polytetrafluoroethylene and/or polyether ether ketone.

As shown in FIG. 1, the switching rail 3 is movable (e.g., laterally, horizontally) relative to the stationary rail 2 in the direction of the arrow Q. Thus, the exposed bearing surface 4X of the lubricious liner 4 is in sliding engagement with exterior surface 3X of the mounting flange 3F.

As shown in FIG. 4, in some embodiments the railway switch system 10 includes a first scraper 21 having a mounting end 21A and a sweeper end 21B and a second scraper 22 having a mounting end 22A and a sweeper end 22B. The mounting ends 21A and 22A are secured to the opposing lateral sides of the mounting flange 3F. The sweeper ends 21B and 22B are in sliding engagement with the exposed bearing surface 4X of the lubricious liner 4 to sweep or scrape debris or contamination away from a sliding interface between the exposed bearing surface 4X of the lubricious liner 4 and the second exterior surface 3X of the mounting flange 3F. In some embodiments, the scrapers 21 and 22 are a brush and/or a flexible material such as a polymer, rubber or synthetic rubber.

As shown in FIG. 7, in some embodiments, the lubricious liner 4 has one or more grooves 4G formed therein. The lubricious liner 4 has a thickness T1 and the grooves 4G have a depth D1, that is less than the thickness T1 of the lubricious liner 4. The grooves 4G extend at least partially into the exposed bearing surface 4X of the lubricious liner 4. The grooves 4G are configured to receive and discharge wear debris and contamination therefrom. In some embodiments, the grooves 4G intersect one another.

Referring to FIG. 2, the railway switch system 10 is similar to the railway switch system 10 illustrated in FIG. 1. Therefore, similar components are labeled with the same element numbers as those used in FIG. 1. The notable difference between the railway switch system 10 of FIG. 1 and the railway switch system 10 of FIG. 2 is that the railway switch system 10 of FIG. 2 further includes a counter-face layer 9 removably retained on the mounting flange 3F of elongate rail 3 (e.g., clipped to the mounting flange 3F). An exterior surface 9X of the counter-face layer 9 is in sliding engagement with the exposed bearing surface 4X of the lubricious liner.

As shown in FIG. 5, the railway switch system 10 includes a first scraper 21 having a mounting end 21A and a sweeper end 21B and a second scraper 22 having a mounting end 22A and a sweeper end 22B. The mounting ends 21A and 22A are secured to the opposing lateral sides of the counter-face layer 9. The sweeper ends 21B and 22B are in sliding engagement with the exposed bearing surface 4X of the lubricious liner 4 to sweep or scrap debris or contamination away from a sliding interface between the exposed bearing surface 4X of the lubricious liner 4 and the exterior surface 9X of the counter-face layer 9. In some embodiments, the scrapers 21 and 22 are a brush and/or a flexible material such as a polymer, rubber or synthetic rubber.

Referring to FIG. 3, the railway switch system 10 is similar to the railway switch system 10 illustrated in FIGS. 1 and 2. Therefore, similar components are labeled with the same element numbers as those used in FIGS. 1 and 2. The notable difference between the railway switching system 20 of FIG. 3 and the railway switches of FIGS. 1 and 2 is that the lubricious liner 4′ is mounted on the counter-face layer 9 which is removably secured to the mounting flange 3F in a manner similar to that described above with reference to FIG. 2. As shown in FIG. 3, the lubricious liner 4′ is secured to a substrate, for example, is mounted to the counter-face layer 9 in a manner similar to that described with reference to FIG. 1 for mounting the lubricious liner 4. The exposed bearing surface 4X′ of the lubricious liner 4′ is in sliding engagement with the exterior surface 5X of the base plate 5. In some embodiments, an additional counter-face layer may be disposed between the base plate 5 and the lubricious liner 4′ and secured to the base plate 5. As shown in FIG. 6, a first scraper 21 and a second scraper 22, similar to the scrapers 21 and 22 shown and described with reference to FIG. 5, is secured to the counter-face layer 9 and is in sliding engagement with the exterior surface 5X of the base plate 5 to keep debris and contaminants from reaching the lubricious liner 4′.

Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of the appended claims. 

What is claimed is:
 1. A railway switch system comprising: an elongate rail having a mounting flange thereon, the mounting flange having a first exterior surface; a base plate having a second exterior surface that faces the first exterior surface, the elongate rail being supported by and laterally movable relative to the base plate; a lubricious liner disposed between the base plate and the mounting flange and mounted in parallel engagement on top of a substrate, the substrate being one of: (a) the first exterior surface, (b) the second exterior surface, and (c) a third exterior surface of an intervening plate disposed between the base plate and the mounting flange; the lubricious liner: (i) having an exposed bearing surface, (ii) having a first width, (iii) extending continuously across the first width, and (iv) being substantially planar; and wherein the lubricious liner consists of a non-metallic substantially graphite free material consisting of a blend of polymer resin, polymer fibers and a polymer lubricant.
 2. The railway switch system of claim 1, wherein the polymer resin is selected from the group consisting of nylon, polyester, epoxy, silicate, nitrile phenolic, phenolic and polyimide resins.
 3. The railway switch system of claim 1, wherein the polymer fibers are thermoplastic fibers comprising at least one of an aramid, glass, polytetrafluoroethylene and polyether ether ketone.
 4. The railway switch system of claim 1, wherein the polymer lubricant comprises at least one of polytetrafluoroethylene and polyether ether ketone.
 5. The railway switch system of claim 1, wherein the lubricious liner is bonded to the substrate.
 6. The railway switch system of claim 1, wherein the lubricious liner is mechanically secured to the substrate by at least one of an epoxy, an adhesive, mechanical fasteners and combinations thereof.
 7. The railway switch system of claim 1, wherein the base plate is secured to a sub-plate by at least one of welding, mechanical fasteners and combinations thereof.
 8. The railway switch system of claim 1, wherein the exposed bearing surface is in sliding engagement with one of the first exterior surface, the second exterior surface and the third exterior surface.
 9. The railway switch system of claim 1, further comprising a scraper secured to the mounting flange and in sliding engagement with the exposed bearing surface of the lubricious liner.
 10. The railway switch system of claim 9, wherein the scraper comprises at least one of a brush and a flexible material.
 11. The railway switch system of claim 1, further comprising a counter-face layer removably retained on the elongate rail and in sliding engagement with the exposed bearing surface of the lubricious liner.
 12. The railway switch system of claim 11, further comprising a scraper secured to the counter-face layer and in sliding engagement with the exposed bearing surface of the lubricious liner.
 13. The railway switch system of claim 12, wherein the scraper comprises at least one of a brush and a flexible material.
 14. The railway switch system of claim 1, further comprising a counter-face layer removably retained on the first exterior surface of the base plate and in sliding engagement with the exposed bearing surface of the lubricious liner.
 15. The railway switch system of claim 1, wherein: the elongate rail extends along a longitudinal axis thereof; the mounting flange has a second width measured perpendicular to the longitudinal axis; and the first width of the lubricious liner is at least as great as the second width of the mounting flange.
 16. The railway switch system of claim 1, wherein the lubricious liner comprises at least one groove extending at least partially into the exposed bearing surface of the lubricious liner, the at least one groove being configured to receive and discharge wear debris and contamination.
 17. A railway switch system comprising: an elongate rail having a mounting flange thereon, the mounting flange having a first exterior surface; a base plate having a second exterior surface that faces the first exterior surface, the elongate rail being supported by and laterally movable relative to the base plate; a lubricious liner disposed between the base plate and the mounting flange and mounted in parallel engagement on top of a substrate, the substrate being the second exterior surface, and the lubricious liner: (i) having an exposed bearing surface, (ii) having a first width, (iii) extending continuously across the first width, and (iv) being substantially planar; wherein the lubricious liner consists of a non-metallic substantially graphite free material consisting of a blend of polymer resin, polymer fibers and a polymer lubricant; and comprising a counter-face layer removably retained on the mounting flange and in sliding engagement with an exposed bearing surface of the lubricious liner.
 18. A railway switch system comprising: an elongate rail having a mounting flange thereon, the mounting flange having a first exterior surface; a counter-face layer removably retained on the mounting flange; a base plate having a second exterior surface that faces the first exterior surface, the elongate rail being supported by and laterally movable relative to the base plate; a lubricious liner disposed between the base plate and the mounting flange and mounted in parallel engagement on top of a substrate, the substrate being the counter-face layer, and the lubricious liner: (i) having an exposed bearing surface, (ii) having a first width, (iii) extending continuously across the first width, and (iv) being substantially planar; wherein the lubricious liner consists of a non-metallic substantially graphite free material consisting of a blend of polymer resin, polymer fibers and a polymer lubricant; and an exposed bearing surface of the lubricious liner is in sliding engagement with the second exterior surface of the base plate. 